I've used 6006 for 15 years. In 6 oz tins, I use cd 7 or 8 almost always. In 11 oz tureens, I double wick with z-32 or z-28. I always use 10% fo. We have done 100s of fundraisers and never had a problem. Some fos just don't throw so don't use them. We don't cure our candles but they might be stronger at 2 wks. In 15 yrs, we have gotten 1 bad case of wax. You'll know if wax is bad, it won't burn. I used to buy fos direct from Agilex but now use fos from BCN, Aztec, Fragrance Buddy, WSP and Lone Star. I'm not sure you are using good fos. IMHO